MiraLAX is an containing the active ingredient polyethylene glycol 3350 (PEG 3350) . It works by drawing water into the colon to hydrate and soften stool, typically producing a bowel movement within 1 to 3 days . Key Details for OTC Use What is Polyethylene glycol (Miralax) used for? - GoodRx
Yes, you can buy over the counter (OTC) . While it was originally a prescription-only medication, it switched to OTC status in 2007 and is now widely available at national drugstore chains, supermarkets, and mass merchandisers.